I have six, week-old chicks. I asked my feed store for medicated starter crumbles and the guy said, "You don't want crumbles. Any kind of mash is good and most people don't bother with medicated" So I am feeding them mash. They are eating well and seem healthy and energetic and are growing fast. But are they getting what they need? I got them at four days old, so they've had four days of mash. Can anyone help?